Frozen drinks such as an ice cream, a smoothie or a slush drink meet different tastes for consumers especially in summer, and are becoming more and more popular with the consumers. In the related art, a refrigerating device used to prepare the frozen drinks includes an evaporator, a compressor, a condenser, a throttling element and so on, in which the raw material (for example, one of water, a dry power ingredient, a solution ingredient, a mixer of water and the dry power ingredient and a mixer of water and the solution ingredient) used to prepare the frozen drinks is refrigerated to form the frozen drinks in one step via the evaporator. With the method for preparing the frozen drinks, the compressor is demanded to start and stop frequently, which influences a service life of the compressor, adds the energy consumption, in addition, time for refrigeration is long as the raw material is refrigerated to form the frozen drink in one step, which influences a taste of the frozen drinks, and a control of the refrigerating device is complicated.